1. Field of the Invention
The present invention generally relates to systems for automatically turning road wheels and more particularly to, an automatic road wheel steering system utilizing a strut-type suspension.
2. Description of the Related Art
A strut-type suspension, better known as MacPherson-strut suspension is light in weight and simple in structure and has, thus, been used in many compact cars. A typical strut-type suspension includes a strut with its upper end fixed to a vehicle body. The strut has its lower end a ball joint through which a control arm is attached to a spindle. A shock absorber is built into the upper section of the strut, and a coil spring fits around the shock absorber. See "6th edition, Brakes, Suspension, and Steering" by William H. Crouse and Donald L. Anglin (McGraw-Hill Book Company).
Japanese utility model publication No. 59-94976 discloses a strut-type suspension having a shock strut with its upper end rotatably attached to a vehicle body through a suitable bearing assembly, and its lower end having an integral spindle on which a wheel is mounted. A system is provided to automatically turn each steerable wheel. This system generally includes an electric motor attached to the lower side of the vehicle body adjacent to the strut. The output shaft of the motor is connected to the strut through a flexible long shaft by which torque is transmitted to assist turning of the steerable wheel. However, there are a few disadvantages to this system. It is complicated, and is subject to damage because of its location.